Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net loss	$ (89,535)	$ (10,294)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock based compensation expense	2,110	2,025
Issuance of common stock for payment of compensation	78	137
Issuance of common stock in exchange for services	302	83
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(166)	176
Accounts payable	8,032	2,190
Accrued expenses	9,326	1,682
Net cash used in operating activities	(69,853)	(4,001)
Investing activities:
Purchase of intangible assets	(20)
Net cash used in investing activities	(20)
Financing activities:
Net proceeds from issuance of common stock	139,760	185
Proceeds from exercise of stock options	572	325
Proceeds from exercise of warrants	10
Net proceeds from issuance of convertible notes	467	1,275
Net proceeds from issuance of PPP loan	83
Net proceeds from issuance of bridge notes	350	2,050
Payments on PPP loan	(83)
Payments on bridge notes	(2,400)
Payments on convertible notes	(518)
Payments on notes payable to vendors	(775)	(505)
Net cash provided by financing activities	137,466	3,330
Net increase (decrease) in cash, cash equivalents and restricted cash	67,593	(671)
Cash, cash equivalents and restricted cash, beginning of period	214	885
Cash, cash equivalents and restricted cash, end of period	67,807	214
Supplemental cash flow disclosure:
Cash paid for interest	672	13
Supplemental disclosure of non-cash investing and financing activities:
Conversion of notes payable and related accrued interest and fees to common stock	4,316	981
Beneficial conversion feature of convertible notes		143
Issuance of stock options in lieu of cash compensation	180	207
Issuance of warrants for services	$ 2,070